Antibacterial activity of a silver-incorporated vancomycin-modified mesoporous silica against methicillin-resistant Staphylococcus aureus.

Since conventional antibiotics are almost ineffective on methicillin-resistant Staphylococcus aureus (MRSA) strains, designing their antibacterial alternatives is necessary. Besides, the use of vancomycin is applied for specific detection of the bacteria. Silver-incorporated vancomycin-modified mesoporous silica nanoparticles (MSNs@Van@Ag NPs) were designed for detection and treatment of MRSA bacteria. Mesoporous silica nanoparticles (MSNs) were synthesized through the template method, modified with vancomycin, and finally incorporated with silver nanoparticles (Ag NPs). The MSNs@Van@Ag NPs with a homogenously spherical shape, average size of 50-100 nm, surface area of 955.8 m2/g, and thermal stability up to 200°C were successfully characterized. The amount of Ag incorporated into the MSNs@Van@Ag was calculated at 3.9 ppm and the release amount of Ag was received at 2.92 ppm (75%) after 100 h. The in vitro antibacterial susceptibility test showed the MIC of 100 µg mL-1 for MSNs@Van and 50 µg mL-1 for MSNs@Van@Ag, showing in vitro enhanced effect of Ag and vancomycin in the bactericidal process. An in vivo acute pneumonia model was performed and biochemical assays and pathological studies confirmed the nanomedicine's short-term safety for in vivo application. Cytokine assay using ELISA showed that MSN@Van@Ag causes a reduction of pro-inflammatory cytokines and bacterial proliferation leading to alleviation of inflammatory response.

Preparation and characterization of poly(vinyl pyrrolidone)/cellulose nanofiber/Aloe Vera composites as a biocompatible hydrating facial mask.

This study aimed to enhance the properties of polyvinylpyrrolidone (PVP) for use as biocompatible facial masks. To achieve this, nanofibers were developed by blending PVP with cellulose nanofibers (CNFs) and Aloe vera (AV) powder using electrospinning. The results showed that incorporating CNFs and AV into the PVP matrix led to the formation of smooth and uniform nanofibers. In particular, adding 3-6 wt% AV powder in PVP/CNF composites improved fiber diameter distribution and uniformity compared to pure PVP. The PVP/CNF/AV nanofibers exhibited desirable properties for facial mask applications. They displayed 86-93 % porosity, which allowed for efficient moisture absorption capacity of up to 1829 %, and excellent water vapor permeability rate of 3.92 g/m2h. The mechanical properties of the electrospun nanofiber composites were evaluated through tensile testing. The results showed that Young's modulus values decreased progressively with the addition of CNFs and AV powder to the PVP polymer matrix, indicating a plasticizing effect that enhances flexibility. The fracture strain remained similar across all composites, suggesting that CNFs and AV did not significantly weaken the PVP matrix. The tensile strength initially increased with CNF addition but decreased with incremental AV loading. Biocompatibility studies revealed that all nanofibers exhibited excellent fibroblast viability, surpassing 98 %. This indicates that incorporating CNFs and AV did not compromise cell viability, further highlighting the suitability of the PVP/CNF/AV composites for facial mask applications.

Preparation, Characterization and In vitro Evaluation of Insulin-PHBV Nanoparticles/Alginate Hydrogel Composite System for Prolonged Delivery of Insulin.

PURPOSE: In the present study, biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles (NPs) containing insulin were loaded in sodium alginate/jeffamine (ALG/jeff) hydrogel for prolonged delivery of insulin. The main aim of this work was to fabricate an efficient insulin delivery system to improve patient adherence by decreasing the repetition of injections. METHODS: Swelling and morphological properties and crosslinking efficiency of ALG/jeff hydrogel were assessed. The composite hydrogel was prepared by adding PHBV NPs to ALG/jeff hydrogel concurrently with crosslinking process. The morphology and loading capacity of composite hydrogel were analyzed. RESULTS: Circular dichroism measurement demonstrated that insulin remains stable following fabrication process. The release profile exhibited 54.6 % insulin release from composite hydrogel within 31 days with minor initial burst release equated to nanoparticles and hydrogels. MTT cell viability analysis was performed by applying L-929 cell line and no cytotoxic effect was observed. CONCLUSIONS: Favorable results clearly introduced fabricated composite hydrogel as an excellent candidate for drug delivery systems and also paves the route for prolonged delivery systems of other proteins.

Symptomatic metastasis prediction with serial measurements of CA 15.3 in primary breast cancer patients.

BACKGROUND: CA 15.3 is elevated in most patients with distant metastatic breast cancer who had prognostic information. The present study was performed to estimate predictive ability of CA 15.3 in assessment of symptomatic metastasis in patients with breast cancer. MATERIALS AND METHODS: During five years, 159 primary breast cancer patients were evaluated. A total of 2226 determination of serum CA 15.3 (14 per patient) were performed. We performed contemporary clinical examinations with CA 15.3 measurements at the time of diagnosis, end of chemotherapy, every three months in the first two years and every six months in the second two years of follow-up period. Imaging studies were performed if clinical or laboratory examinations (abnormal serum levels of CA 15.3) suspected symptomatic metastasis. Metastasis in participants was confirmed by imaging study in symptomatic patients. RESULTS: There was no significant increase in CA 15.3 tumor markers during chemotherapy (P = 0.08). There was a significant relationship between CA 15.3 positive results and metastasis situation (P = 0.00). Mean of maximum CA 15.3 level in metastatic patients (52.72±27.09) was significantly higher than non-metastatic patients (27.58±13.46; P = 0.00). CA 15.3 abnormality (OR, 1.07; 95% CI: 1.04-1.11; P value, 0.01) and abnormal lymph nodes remained as predictor of metastasis (OR: 1.16; 95% CI: 1.05-1.28; P value < 0.0001). CONCLUSION: CA 15.3 is one of the predicting factors for symptomatic metastasis.